On Wed, 2020-04-15 at 16:55 +0200, Lars-Peter Clausen wrote: > [External] > > On 4/15/20 3:56 PM, Ardelean, Alexandru wrote: > > On Tue, 2020-04-14 at 19:06 +0100, Jonathan Cameron wrote: > > > [External] > > > > > > On Tue, 14 Apr 2020 11:36:56 +0300 > > > Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote: > > > > > > > The final intent is to localize all buffer ops into the > > > > industrialio-buffer.c file, to be able to add support for multiple > > > > buffers > > > > per IIO device. > > > > > > > > We only need a chardev if we need to support buffers and/or events. > > > > > > > > With this change, a chardev will be created: > > > > 1. if there is an IIO buffer attached OR > > > > 2. if there is an event_interface configured > > > > > > > > Otherwise, no chardev will be created. > > > > Quite a lot of IIO devices don't really need a chardev, so this is a > > > > minor > > > > improvement to the IIO core, as the IIO device will take up fewer > > > > resources. > > > > > > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> > > > > --- > > > > > > > > Changelog v1 -> v2: > > > > * split away from series 'iio: core,buffer: re-organize chardev > > > > creation'; > > > > i'm getting the feeling that this has some value on it's own; > > > > no idea if it needs 'Fixes' tag; it is a bit fuzzy to point to a > > > > patch > > > > which this would be fixed by this; i'm guessing it would be fine > > > > without one > > > I'd argue it's an 'optimization' rather than a fix :) > > > > > > Still looks good to me but I'd like it to sit for a little while to > > > see if anyone points out something we are both missing! > > > > > This is not good. > > It seems that I did not properly test all cases. > > I had to break a device to not have an event_interface to notice that the > > sysfs > > doesn't get instantiated either because device_add is missing. > > > > Will do another try. > > I think you also have to make the `indio_dev->dev.devt = ...` > conditional. Or conditionally use device_add() instead of device_add_cdev(). > > If you go for the former you need to call cdev_device_del() > unconditionally, for the latter call device_del() or cdev_device_del() > depending on whether the cdev was registered. I was thinking of conditionally using cdev_device_add/del() somehow. But, this complicates the rest of the series a bit. And I am thinking of how to simplify it. Anyway, this will go back to the series ¯\_(ツ)_/¯ > > - Lars > >
